Pneumatic vehicle tyre with circumferential channel

Abstract

A pneumatic vehicle tire having a tread with profiling and at least one circumferential groove which runs in encircling fashion in the circumferential direction and is formed to a profile depth. At least over part of the circumference the groove has a cross section perpendicularly to the circumferential direction made up of at least two groove portions adjoining one another in a radial direction. A first groove portion is symmetrical with respect to the radial direction. The width of said groove portion in the axial direction is less than 3 mm and does not vary by more than 10%. A second radially inner groove portion is made wider in the axial direction in comparison with the first groove portion. It has the largest cross-sectional area of all the groove portions. Its cross-sectional area is asymmetrical to the radial direction, extends on both sides of the radial direction and has an edge without corners in the bottom region of the circumferential groove.

The invention claimed is: 
     
         1 . A pneumatic vehicle tire comprising:
 a tread ( 2 ) having a profiling and which has a circumferential groove ( 1 ) which runs in encircling fashion in a circumferential direction of the tire;   the groove being formed to a profile depth PT and comprising, in cross section perpendicularly to the circumferential direction, a first groove portion ( 4 ) and a second groove portion ( 5 ) adjoining one another in a radial direction R, with the second groove portion ( 5 ) being radially inward of the first groove portion ( 4 ),   the first groove portion ( 4 ), in cross section, being symmetrical with respect to the radial direction R and having a width in the axial direction A perpendicular to the radial direction R that is less than 3 mm and does not vary by more than 10%,   the second groove portion ( 5 ), in cross section, being wider in the axial direction A in comparison with the first groove portion ( 4 ), and having the largest cross-sectional area of all the groove portions, and the cross-sectional area of the second groove portion ( 5 ) being asymmetrical to the radial direction R, and extending on both sides of the radial direction R and having a border without corners in a bottom region ( 6 ) of the circumferential groove ( 1 ),   wherein the cross-sectional area of the second groove portion ( 5 ) between an imaginary line running in the radial direction R and the side ( 8 ) of the circumferential groove ( 1 ) pointing to the center of the vehicle tire is between 10% smaller and 15% larger than the cross-sectional area of the second groove portion ( 5 ) between the imaginary line running in the radial direction R and the side ( 9 ) of the circumferential groove ( 1 ), which points to the outside of the vehicle pneumatic tire;   wherein, in cross section, the imaginary line running in the radial direction R is centrally axially located to axially bisect the width in the axial direction A of the first groove portion ( 4 ).   
     
     
         2 . The tire of  claim 1 , wherein edges in the bottom region ( 6 ) of the circumferential groove ( 1 ) in the second groove portion ( 5 ) only have rounded portions. 
     
     
         3 . The tire of  claim 1 , wherein in the bottom region ( 6 ) of the circumferential groove ( 1 ), a side ( 8 ) of the circumferential groove ( 1 ) in the second groove portion ( 5 ) has a curvature R 2  with a smallest radius of curvature and faces a center of the tire. 
     
     
         4 . The tire of  claim 3 , wherein in the bottom region ( 6 ) of the circumferential groove ( 1 ), on the side ( 8 ) of the circumferential groove ( 1 ) in the second groove portion ( 5 ) which faces a center of the pneumatic vehicle tire, the smallest radius of curvature R 2  is at least 20% smaller than a smallest radius of curvature R 1  of a curvature of an opposite side ( 9 ) of the circumferential groove ( 1 ) in the second groove portion ( 5 ). 
     
     
         5 . The tire of  claim 1 , wherein the circumferential groove ( 1 ) is an outer groove ( 10 ,  11 ) of the pneumatic vehicle tire. 
     
     
         6 . The tire of  claim 1 , wherein over at least 35% of the height H 2  of the second groove portion ( 5 ) in the radial direction R, the cross-sectional area of the second groove portion ( 5 ), starting from the bottom region ( 6 ) of the circumferential groove ( 1 ), is asymmetrical to the radial direction R. 
     
     
         7 . The tire of  claim 1 , wherein over at least 70% of the height H 2  of the second groove portion ( 5 ) in the radial direction R, the cross-sectional area of the second groove portion ( 5 ), starting from the bottom region ( 6 ) of the circumferential groove ( 1 ), is asymmetrical to the radial direction R. 
     
     
         8 . The tire of  claim 1 , wherein, in cross section, a maximum width Gwmax of the cross-sectional area of the second groove portion ( 5 ) perpendicular to the radial direction R is 20% smaller to 50% greater than the maximum height H 2  of the cross-sectional area of the second groove portion ( 5 ) in the direction of the radial direction R.